The stability constants of the complexes between the trivalent lanthanide series of cations and series of azo-β-diketone ligands are reported. The measurements were conducted at 30° at an ionic strength of zero, in 100% methanol. The relation between the overall stability constant (log β2) and atomic number of the lanthanide elements, shows a buffer zone at the gadolinium area. The relation between (log β2) and the basicity of the studied ligands (ΣpK's) are also, discussed. The overall stability values obtained reflected a great affinity of the organic ligands for chelation with lanthanide ions. 相似文献
Summary. Nitrilimines were prepared from N-arylhydrazono chlorides and reacted with -alanine yielding the corresponding amidrazones, which were treated with 1,1-carbonyldiimidazole in THF affording the hitherto unknown 3-acetyl-1-aryl-1,4,5,6-tetrahydro-1,2,4-triazepin-7-ones. 相似文献
The kinetic study of competitive consecutive reactions presents difficulties owing to the complexity of the mathematical integration of differential equation systems. Many investigators adopted methods using graphs of experimental data to determine the kinetic constants of a reaction. We propose, in this work, a direct determination of these constants based on thermograms recorded with a Calvet conduction microcalorimeter using a computing program which includes numerical integration of differential equation systems, signal convolution with an experimental function of apparatus (to get rid of the inertness of the detector—recorder system) and the optimization of the adopted model parameters. We applied this exploitation process to the alkaline hydrolysis of some diester of diols or dicarboxylic acids in aqueous solution. 相似文献
The heat capacity changes during the glass transition of TeO2---TlO0.5 glasses containing AgI or (AgI)0.75(TlI)0.25 up to mole fractions of 0.4 or 0.55 have been measured by differential scanning calorimetry. The glass transition temperatures of the binary compositions decrease with increasing TlO0.5/TeO2 ratio. With rising Ag+ concentration, the cohesion of the glass network is weakened and the structural contributions to the relaxation phenomenon as well as its activation enthalpies diminish. There is no interaction between the iodide in probably crystalline form and the host glass network. Compared with binary and ternary silver tellurite glasses, the corresponding thallium tellurite compositions are less stable. 相似文献
InCl3 was found to be a mild and effective catalyst for the simple and efficient synthesis of spiro-perimidine derivatives by the reaction of naphthalene-1,8-diamine and active carbonyl compounds in water at room temperature. This protocol includes some important aspects like the use of water as a “green” reaction medium, good yielding of products and mild reaction conditions. 相似文献
A nanosensor, based on 8-hydroxyquinoline functionalized graphene oxide, was developed for the fluorescence detection of Zn2+. It showed high selectivity and sensitivity for Zn2+ion in aqueous solution over other metal ions such as Li+, Na+, Ca2+, Mg2+, Al3+, Cd2+, Co2+, Cu2+, Hg2+, Ni2+, Pb2+, Fe2+, Fe3+and Cr3+. Due to the linearity of the emission intensity toward Zn2+ concentration, fluorescent technique could be used for the detection of Zn2+ ion even at very low concentrations. 相似文献
Power dissipation problem is one of the most challenging problems in designing conventional electronic circuits. One of the best approaches to overcome this problem is to design reversible circuits. Nowadays, reversible logic is considered as a new field of study that has various applications such as optical information processing, design of low power CMOS circuits, quantum computing, DNA computations, bioinformatics and nanotechnology. Due to the vulnerability of the digital circuits to different environmental factors, the design of circuits with error-detection capability is considered a necessity. Parity preserving technique is known as one of the most famous methods for providing error-detection ability. Multiplication operation is considered as one of the most important operations in computing systems, which can play a significant role in increasing the efficiency of such systems. In this paper, two efficient 4-bit reversible multipliers are proposed using the Vedic technique. The Vedic technique is able to increase the speed of multiplication operation by producing partial products and their sums simultaneously in a parallel manner. The first architecture lacks the parity preserving potential, while the second architecture has the ability parity preserving. Since a 4-bit Vedic multiplier includes 2-bit Vedic multipliers and 4-bit ripple carry adders (RCA), so in the first design, TG, PG and FG gates have been used to design an efficient 2-bit reversible Vedic multiplier, as well as PG gate and HNG block have been applied as a half-adder (HA) and full-adder (FA) in the 4-bit RCAs. Also, in the second design, 2-bit parity preserving reversible Vedic multiplier has been designed using FRG, DFG, ZCG and PPTG gates as well as ZCG and ZPLG blocks have been utilized as HA and FA in the 4-bit RCAs. Proposed designs are compared in terms of evaluation criteria of circuits such as gate count (GC), number of constant inputs (CI), number of garbage outputs (GO), quantum cost (QC), and hardware complexity. The results of the comparisons indicate that the proposed designs are more efficient compared to available counterparts.